The LCD (Liquid Crystal Display) has been widely used in electronic products such as notebook computers, flat TV sets or mobile phones due to its advantages such as low radiation, small volume, low energy consumption and so on.
The LCD is formed by staggering pixel matrices located in the horizontal direction and the vertical direction. When the LCD displays, a data driving circuit can latch the input display signals and the clock signal timing sequentially, and convert the input display data into an analog signal and then input it into data lines of a liquid crystal panel; a gate driving circuit can convert the input clock signals into a voltage for controlling pixels to turn on/turn off through shift registers, and apply it to gate lines of the liquid crystal panel row by row.
In order to further reduce the production cost of liquid crystal display products, the gate driving circuit known in the art typically uses the GOA (Gate Driver On Array) design to integrate the TFT (Thin Film Transistor) gate switch circuit on the array substrate of the display panel to form scan driving for the display panel. Therefore, the gate driving integrated circuit part can be omitted, which can reduce the product cost in terms of both material cost and manufacturing process. In addition, the display panel can be made in a beautiful design with symmetric sides and a narrow frame. The gate switch circuit integrated on the array substrate by the GOA technology is also referred to as a GOA circuit or a shift register circuit.
In the GOA circuit known in the art, the turning on or turning off of a TFT is needed to realize the turning on or turning off of a gate line in a corresponding row. In particular, it is possible to input a control signal to a TFT of the GOA circuit through a signal input terminal to turn off the TFT, thereby controlling the gate line in a row corresponding to the TFT not to output a signal. However, when the control signal is an AC (Alternate Current) square wave, the OFF state of the TFT will have interruption intervals; therefore, it cannot be guaranteed that the gate line in the row corresponding to the TFT always keeps in the state of no signal outputting during the non-output period. If a DC (Direct Current) signal is used to control the turning off of the TFT, although the occurrence of the above interruption intervals can be avoided, the threshold voltage of the TFT which is at the DC high level for a long time will shift, and finally the TFT cannot be normally turned on. Thereby, the stability of the TFT and the GOA circuit is reduced.